I recently acquired from ebay a used Sprint HTC One M7 for cheap because the guy couldn't unlock it.
I followed all the tutorials and guides here, and got the phone unlocked, TWRP recovery and SuperSU flashed, S-OFF, and a custom rom (Viper) flashed on it successfully.
I am from France and my network operator is Free.fr. I used both the *#*#4636#*#* and the Mobile settings to enable GSM and the phone, SMS, and 3G data are all working properly.
However, my operator allows for 4G LTE as well and I would like to use it if possible, while retaining the use of the Phone itself (making calls, texts etc).
The way it works for Free.fr is that I have to login on their website, and enable 4G manually. The server will then check if my phone has 4G LTE compatibility and enable it if it does, but everytime I try it tells me my phone is not 4G ready.
Is there anyway to do this? A guide or tutorial out there perhaps?
edit: more info:
It seems I need 2600 MHz frequency for 4G to work with my operator, could it be that the Sprint version cannot handle this? Any solutions?